docs: def _get_powerinfo(self, data):
          '''Return battery voltage and tx power '''
          power_info = (data[13] & 0xFF) << 8 | (data[14] & 0xFF)
          battery_voltage = rshift(power_info, 5) + 1600
          tx_power = (power_info & 0b11111) * 2 - 40
  
          if rshift(power_info, 5) == 0b11111111111:
              battery_voltage = None
          if (power_info & 0b11111) == 0b11111:
              tx_power = None
  
          return (round(battery_voltage, 3), tx_power)